Expertises
Mathematics
- Banach Algebras
- Homomorphism
- Numerical Range
- Extremal Function
- Double Layer Potential
- Functional Calculus
- Sharp Bound
- Von Neumann
Organisaties
Publicaties
2025
The algebraic numerical range as a spectral set in Banach algebras (2025)Canadian journal of mathematics. Blazhko, H., Homza, D., Schwenninger, F. L., de Vries, J. & Wojtylak, M.https://doi.org/10.4153/S0008414X25000124The algebraic numerical range as a spectral set in Banach algebras (2025)Canadian journal of mathematics (E-pub ahead of print/First online). Blazhko, H., Homza, D., Schwenninger, F. L., de Vries, J. & Wojtylak, M.https://doi.org/10.4153/S0008414X25000124
2024
A sharp bound for the functional calculus of ρ-contractions (2024)[Working paper › Preprint]. ArXiv.org. de Vries, J. & Schwenninger, F. L.https://doi.org/10.48550/arXiv.2412.02326The algebraic numerical range as a spectral set in Banach algebras (2024)[Working paper › Preprint]. ArXiv.org. Blazhko, H., Homza, D., Schwenninger, F. L., de Vries, J. & Wojtylak, M.https://doi.org/10.48550/arXiv.2410.10678The double-layer potential for spectral constants revisited (2024)[Working paper › Preprint]. ArXiv.org. Schwenninger, F. L. & de Vries, J.https://doi.org/10.48550/arXiv.2409.15954A unifying approach to von Neumann’s inequality and Crouzeix’s conjecture (2024)[Contribution to conference › Poster] 59e Nederlands Mathematisch Congres 2024. de Vries, J.On Abstract Spectral Constants (2024)In Operator and Matrix Theory, Function Spaces, and Applications: International Workshop on Operator Theory and its Applications 2022, Kraków, Poland (pp. 335-350) (Operator Theory: Advances and Applications; Vol. 295). Springer. Schwenninger, F. L. & de Vries, J.https://doi.org/10.1007/978-3-031-50613-0_15
2023
On Abstract Spectral Constants (2023)[Working paper › Preprint]. ArXiv.org. Schwenninger, F. L. & de Vries, J.https://doi.org/10.48550/arXiv.2302.05389
Onderzoeksprofielen
Vakken collegejaar 2024/2025
Vakken in het huidig collegejaar worden toegevoegd op het moment dat zij definitief zijn in het Osiris systeem. Daarom kan het zijn dat de lijst nog niet compleet is voor het gehele collegejaar.
Adres

Universiteit Twente
Zilverling (gebouwnr. 11), kamer 3006
Hallenweg 19
7522 NH Enschede
Universiteit Twente
Zilverling 3006
Postbus 217
7500 AE Enschede